Ron Shaich, Panera Bread founder, chairman and CEO, speaks to attendees at the 2014 Social Innovation Summit presented by Landmark Ventures at United Nations on May 29, 2014, in New York City. (Stephen Lovekin/Getty Images for Social Innovation Summit)

Panera Bread is buying Au Bon Pain, and founder Ron Shaich is stepping down as CEO.

The companies did not disclose on Wednesday how much Panera was paying for Au Bon Pain, an acquisition it says will boost its presence at airports, hospitals and colleges. Those are places where chains like Starbucks and Dunkin' Donuts are strong.

Shaich, 63, will be replaced as CEO on Jan. 1 by Blaine Hurst, who oversees Panera's restaurants. Shaich will stay on as Panera's chairman, and will continue to work on the chain's strategy and future acquisitions.

Shaich said Wednesday that he's not exactly stepping out: "I'm more broadening," he said in an interview. He also said it was "too early to comment" on how Panera will use Au Bon Pain, or whether the brand will continue.

It's been a year of change for Panera: In July, it was bought and taken private for more than $7 billion by JAB Holding Co., a European company that controls Krispy Kreme, Peet's Coffee and other chains.

At the time, Shaich said he wouldn't be leaving the CEO post: "They'll need to carry me out with my boots on," he told The Associated Press in April. But in a statement Wednesday, he called it "the right time for me to step down as CEO while still staying involved in the business."

He'll have more time to work with Panera's owners on deals, like the Au Bon Pain one, and focus on his personal investments, though he declined to say what those were.

Shaich created Au Bon Pain Co. with a partner in 1981. It became a public company in 1991 and Au Bon Pain bought a bakery two years later that was renamed Panera. Au Bon Pain was sold off in 1999 so that the company could focus on Panera.

St. Louis-based Panera now has more than 2,000 restaurants and employs about 100,000. Boston-based Au Bon Pain has about 300 locations. The deal is expected to close by the end of the year.

Andrew Alvarez, a food industry analyst at IBISWorld, said the deal would help Panera better compete with the coffee chains that have locations in similar places as Au Bon Pain.

Both Panera and Au Bon Pain sell sandwiches, soups, salads and baked goods. In recent years, Shaich has been tweaking Panera's menu to appeal to Americans who are increasingly looking to avoid processed food. At the start of the year, Panera said it removed artificial preservatives, sweeteners, flavors and colors from all its food. And in March it began selling drinks, such as plum ginger hibiscus tea, as an alternative to the more sugary soda it sells.